The Ministry of Public Security is set to investigate the unusually high number of foreign cars that entered the country last year.

In the first 11 months of 2012, Viet Kieu (overseas Vietnamsese) had brought back to the country 71 vehicles, customs data showed, five times the previous year's total.

An overseas Vietnamese is allowed to bring back one car only, which is exempt from import and value added taxes.

Most of the cars were new and super luxurious makes and models like the Rolls-Royce Phantom, the Bugatti Veyron, and various Porches, news website Vietnamnet reported.

The tax on these cars, if paid, would have come to at least 1 billion dong (US$48,000).

The customs department said the police would check the documents of cars imported since mid-2011. That was when the government started to tighten restrictions on car imports, regulating that importers have to prove they are representative dealers of foreign auto companies.

The condition, which many importers said is hard to fulfill, is believed to have caused an increase in car smuggling.

Police and customs offices in Hanoi, Ho Chi Minh City, and four provinces will temporarily seize all cars imported by Vietnamese expats for investigation.